On 10/13/21 11:57 AM, Christoph Hellwig wrote: > On Wed, Oct 13, 2021 at 11:46:04AM -0600, Jens Axboe wrote: >> On 10/13/21 11:22 AM, Christoph Hellwig wrote: >>> On Wed, Oct 13, 2021 at 10:49:35AM -0600, Jens Axboe wrote: >>>> If we don't use an IO scheduler or have shared tags, then we don't need >>>> to call into this external function at all. This saves ~2% for such >>>> a setup. >>> >>> Hmm. What happens if you just throw an inline tag onto >>> blk_mq_get_driver_tag? >> >> I'd be surprised if that's any different than my patch in terms of >> performance, the fast path would be about the same. I don't feel >> strongly about it, can do that instead. > > I find the double indirection in your patch a bit confusing. Not a big > deal if it is actually required, but if we can avoid that I'd prefer > not to add the extra indirection. Tested the variants, and it does seem to be the best one... -- Jens Axboe
